The present invention relates generally to communications in a radio communication system, such as a WLAN (wireless local area network). More particularly, the present invention relates to apparatus, and an associated method, by which to identify whether proprietary WLAN radio functions are available to a mobile terminal-access point pair and to activate proprietary WLAN radio functions if such availability is identified. Performance of proprietary WLAN radio functions permits improved communication quality, such as improved handover performance, relative to conventional WLAN operation pursuant, e.g., to the IEEE 802.11 standard.
A communication system is formed, at a minimum, of a transmitting station and a receiving station interconnected by a communication channel. Communication signals generated by the transmitting station are transmitted upon the communication channel to be received by the receiving station.
A radio communication system is a communication system in which at least a portion of the communication channel is formed of a portion of the electromagnetic spectrum. Increased mobility of communications is permitted as a fixed or hard-wired connection is not required to be formed between the transmitting and receiving stations.
A cellular communication system is an exemplary radio communication system. A subscriber to a cellular communication system, when positioned at almost any location throughout an area encompassed by the network infrastructure of the cellular communication system, is able to communicate by way of the system with a mobile terminal.
The network infrastructure of an exemplary cellular communication system includes spaced-apart, fixed-site base stations which include transceivers. In such an exemplary system, each fixed-site base station defines a cell. As the mobile terminal used by the subscriber to communicate with another communication station travels between cells of the system, uninterrupted communication is possible by handing-over communications from one base station to another.
Several analogous types of wireless communication systems have been implemented, and others have been proposed, to encompass limited areas, such as the area encompassed by a building structure or office workplace. Wireless communication systems sometimes referred to as microcellular networks, private networks, and WLANs (wireless local area networks) are exemplary of such systems.
Wireless communication systems are typically constructed pursuant to standards promulgated by a regulatory or quasi-regulatory body. For instance, the IEEE 802.11 standard promulgated by the IEEE (Institute of Electrical and Electronic Engineering) is a wireless LAN standard pertaining generally to the commercial 2.4 GHz wireless LAN (local area network). The 802.11 standard specifies an over-the-air interface between a wireless client, e.g, a mobile terminal, and a base station or access point, as well as among wireless clients. Standards pertaining to a physical layer and an MAC (media access control) layer are set forth in such standard. The standard permits automatic medium sharing between different devices which includes compatible physical layers. Asynchronous data transfer is provided for in the standard, generally by way of the MAC layer which utilizes a CSMA/CA (carrier sense multiple access with collision avoidance) communication scheme.
While the IEEE 802.11 standard provides for wireless communications through the use of mobile terminals constructed to be operable pursuant to such standard, the standard does not adequately provide for real time wireless services. For instance, in the current implementation of the standard, a significant loss of quality is sometimes experienced during handover of communications from one access point to another. Excessive numbers of data frames are susceptible to being lost or delayed, resulting in the loss of communication quality or even termination of communications.
Operational modes different than that set forth in the IEEE 802.11 standard are therefore required, particularly for real time wireless services. Proprietary functions have been proposed which permit improved quality of communications compared to operation pursuant to the existing IEEE 802.11 standard. Access points and mobile terminals operable to perform such proprietary functions are referred to as being proprietary mode capable.
However, both ends of the communication pair, i.e., the mobile terminal and the access point through which the mobile terminal communicates, must be capable of operation in the proprietary mode. If both ends of the communication pair are not together operable pursuant to the proprietary mode, conventional operation pursuant to the IEEE 802.11 standard is instead required.
Therefore, prior to permitting operation of both ends of the communication pair in the proprietary mode, a determination must be made of the ability of both ends of the communication pair together to be operable pursuant to the proprietary mode.
A manner by which to identify whether both ends of the communication pair are together operable in the proprietary mode, to activate both ends of the communication pair to operate in the proprietary mode, and to maintain proprietary mode operation during handover procedures from one access point to another is required.
It is in light of this background information related to wireless communications that the significant improvements of the present invention have evolved.
The present invention, accordingly, advantageously provides apparatus, and an associated method, to identify whether proprietary WLAN radio functions are available to a communication pair formed of a mobile terminal and access point.
The present invention further advantageously provides apparatus, and an associated method, to initiate activation of the proprietary WLAN radio functions subsequent to identifying that both the mobile terminal and access point of the communication pair are together operable pursuant to the proprietary WLAN radio function.
The present invention further advantageously provides apparatus, and an associated method, by which to maintain proprietary-mode of communication during handover of communications from one access point to another.
In one aspect of the present invention, a manner is provided to identify whether devices constructed to be operable in a WLAN, such as that defined in the IEEE 802.11 standard are also together operable pursuant to a proprietary mode of operation to perform proprietary WLAN radio functions. Such proprietary WLAN radio functions are intended to improve the quality of communications relative to the quality of communications provided for during operation pursuant to a conventional, IEEE 802.11 mode of operation.
In a further aspect of the present invention, responsive to identification that both ends of a communication pair formed of a mobile terminal and an access point of the WLAN are together operable pursuant to the proprietary mode, the mobile terminal is activated to be operable pursuant to the proprietary mode rather than the conventional, IEEE 802.11 mode of operation. Improved quality of communications relative to that permitted pursuant to conventional operation pursuant to the IEEE 802.11 standard is possible thereafter.
In a further aspect of the present invention, a manner is provided to assure better that ongoing communications effectuated by a communication pair operating pursuant to the proprietary mode of operation shall continue to be effectuated pursuant to the proprietary mode subsequent to handover of communications from one access point to another access point. In one implementation, the mobile terminal of the communication pair is provided with a list of access points which are capable of operation pursuant to the proprietary mode. The list, a neighboring-AP (access point) list, is used by the mobile terminal, or the network, in the determination of to which access point that handover of communications is permitted. As handovers thereby are only permitted between proprietary mode-capable access points if handover is effectuated only to an access point on the list, better assurances that the communications shall continue to be effectuated pursuant to the proprietary mode of operation are thereby provided. In one implementation, the list is provided to the mobile terminal at selected intervals. In another implementation, the list is provided to the mobile terminal when the mobile terminal is initially activated to be operable pursuant to the proprietary mode. Also, in another implementation, a network prefix or list of network prefixes is provided for the same purpose.
In one implementation, an EUI-64 type of MAC (media access control) layer address is provided to each device operable in the WLAN. The EUI-64 type address is formed of two fields, a company id field and a CDPD M-ES (cellular digital packet data-mobile end system number). Such address is globally unique. Prior to effectuation of communications, the EUI-64 MAC addresses of a communication pair formed of a mobile terminal and access point are compared to identify whether both of the devices are proprietary mode capable. If both devices are determined to be proprietary-mode capable responsive to the comparison, communications are permitted to be effectuated pursuant to the proprietary mode. The mobile terminal is thereafter activated to be operable pursuant to the proprietary mode, and improved communication quality of subsequent communications is possible. Also, when handover of communications is to be effectuated, handover is effectuated, if possible, only to a subsequent access point which also is proprietary mode capable. Continued communications of improved quality levels relative to conventional communications pursuant to the IEEE 802.11 standard are thereby possible.
In these and other aspects, therefore, apparatus, and an associated method, is provided for a radio communication system having a mobile terminal and at least one access point at which to permit communication access of the mobile terminal with network infrastructure. The mobile terminal and the access point together are operable pursuant to a first mode and potentially together operable pursuant to a second mode. The mobile terminal and the at least one access point are each identified by unique identifiers. Identification is made whether the mobile terminal and the access point are together operable pursuant to the second mode. A comparator is coupled to receive indications of the identifier which identifies the mobile terminal. The comparator is also coupled to receive indications of the identifier which identifies the access point. The comparator compares values of the identifiers. The comparator indicates the mobile terminal and the access points together to be operable pursuant to the second mode if the values of the identifiers indicate both the mobile terminal and the access point to be capable of operation pursuant to the second mode. And, the comparator indicates the mobile terminal and the access point together to be operable only pursuant to the first mode if the values of the identifiers fail to indicate both the mobile terminal and the access point operable pursuant to the second mode.
A more complete appreciation of the present invention and the scope thereof can be obtained from the accompanying drawings which are briefly summarized below. The following detailed description of the presently-preferred embodiments of the invention, and the appended claims.